1. Field of the Invention
This invention relates to a switching apparatus for an interior light, such as a room light the like, in a motor vehicle and, in particular, to a switching apparatus for an interior light in a motor vehicle, in which the interior light is turned off after a predetermined delay period from the time when an off command is issued.
2. Statement of the Prior Art
A room light is provided in a motor vehicle to illuminate the interior of the vehicle, for example, in order to see a map at night.
A conventional room light is turned on and off when a user turns on and off a switch provided between the room light and a battery in the motor vehicle.
However, it has been recognized lately that the room light should be used immediately before and after getting into and out of the motor vehicle. Consequently, motor vehicles have been provided with a switching apparatus which automatically turns on and off the room light when the door is opened and closed. This switching apparatus includes a manual three-position changing-over switch provided between the room light and the ground, and a normal open type limit switch which turns on and off upon opening and closing the door.
When the changing-over switch in the switching apparatus is set to the first changing-over position, the room light is connected to the battery and is always turned on, regardless of the opening and closing of the door. When the changing-over switch is set in the second changing-over position, the limit switch is closed to turn the room light on if the door is opened and the limit switch is opened to turn the light off if the door is closed. Further, when the changing-over switch is set in the third changing-over position, the room light is always turned off irrespective of the opening and closing of the door. Accordingly, this switching apparatus turns the room light off and on when the door is closed and opened by opening and closing the limit switch.
However, since the switching apparatus turns the room light on or off simultaneously with the opening or closing of the door, the room light is turned off as soon as the user gets into the motor vehicle and closes the door. If the user wishes to do something immediately after getting into the motor vehicle, the user must either keep the door open or change the changing-over switch from the second or third changing-over position to the first changing-over position, which always turns the room light on.
Thus, recently, there is a motor vehicle provided with a switching apparatus in which the root light is kept on for a predetermined period of time even after the user gets into the motor vehicle and closes the door. However, it is impossible to uniformly determine the period of lighting after closing the door, since there are various users' choices, purposes for use of the motor vehicle, places and circumstances of getting into and out of the vehicle, and the like. That is, the switching apparatus which turns on the room light for a predetermined period of time after closing the door cannot sufficiently meet the requirements of all users.